<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .father {
            width: 600px;
            height: 600px;
            margin: 100 auto;
            position: relative;
            /* 隐藏旋转背面 */
        }
        
        .r,
        .t {
            width: 600px;
            height: 600px;
            border-radius: 50%;
            transition: all 1s;
            border: 1px solid plum;
            background: url(./R-C.jpg) no-repeat;
            position: absolute;
            left: 0;
            margin: 0;
            backface-visibility: hidden;
        }
        
        .father:hover .r {
            transform: rotateY(-180deg);
        }
        
        .t {
            background: url(./R-C1.jpg);
            transform: rotateY(-180deg);
        }
        
        .t {
            z-index: 1;
        }
        
        .father:hover .t {
            transform: rotateY(0deg);
        }
    </style>
</head>

<body>
    <div class="father">
        <div class="r"></div>
        <div class="t"></div>
    </div>
</body>

</html>